1. Field of the Invention
The present invention concerns a paper transport device with cylinders to lead a continuous form paper into and out of a printing installation.
2. Description of the Related Art
Such installations as the printers of electronic computer systems often handle continuous form paper. The paper to be printed on has to be led continuously into the printing device and, after printing, has to be guided continuously out of the printing device. The paper transport is relatively often interrupted by disturbances that may cause the paper to become jammed or blocked. Unreadable print may be the result. Satisfactory paper transport is even more difficult when such a printing device is combined with a sound cover or completely confined in a sound cover box. In such a case, the continuous form paper has to be guided additionally through the sound cover box or the sound cover. Each additional opening means that the sound protection is less.
Different possibilities have been tried to provide an undisturbed paper transport inside and out of printing devices. It is also, for example, well known to lead the continuous form paper over rods, tubes or wooden cylinders to lower tension in the advancing paper. Similarly, special guide posts and wheels have been used to keep movement of the paper in a predetermined direction.
In this context, sound covers have been used in the prior art. In these cases, the continuous form paper from the paper-pile is guided through a slit in the backside of the sound cover to the printing installation. Inside the sound cover, the paper-edges of the continuous form paper are shielded by special devices on the way between the already mentioned slit and the printing installation. When the paper has gone through the printing installation it is guided through a second slit, which is spaced from the first one, outside of the sound cover. The continuous form paper is then collected on a table, on the floor, or in a basket.
But within such sound covers, disturbances in the advancing continuous form paper are frequent. This is especially unpleasant in cases of emergency when nobody is available to clear the way for the paper immediately on the occurrence of a disturbance. Furthermore, the sound of a disturbance within a sound cover often is not transmitted through the entrance and exit slits of the sound cover so that disturbances are difficult to monitor.
The object of the present invention is to provide a paper transport device to guide continuous form paper into and out of a printing device over a long time-period without disturbance. Also, the transport device, when combined with a sound cover or sound cover box for the printing device, guarantees the desired sound proof condition.